韭菜疫病是由烟草疫霉菌侵染引起的一种真菌性病害,病害一旦发生,发展迅速,传播快,会在短时间内使全田发病。韭菜植株地上、地下部分均可发病,尤以假茎和鳞茎发病最重。叶片发病,开始出现暗绿色水渍状病斑,病斑迅速扩展,病部失水缢缩变细,叶片发黄,凋萎下垂,进而出现软腐和叶鞘脱落。湿度大时,病部长出稀疏白色霉层。鳞茎发病时,茎盘 Chive blight is a fungal disease caused by Phytophthora infestans infection. Once a disease occurs, it develops rapidly and spreads quickly, which will cause disease in the whole field in a short period of time. Leek plants on the ground, the ground can be part of the disease, especially in the heaviest incidence of pseudostems and bulbs. The leaves began to appear dark green stains like water spots, rapid expansion of disease spots, shrinkage of the diseased part of the skin shrinks thin, yellow leaves, withered and drooping, leaving soft rot and leaf sheath shedding. When humidity is high, the disease grows sparse white mildew. Bulb onset, stem plate